1. e+ e– 碰撞中喷注内部的 非线性动力学特性的研究 报告人: 陈 刚 （中国地质大学 数学与物理学院 物理系） 2006年10月29日
报告人: 陈 刚 （中国地质大学 数学与物理学院 物理系） 2006年10月29日

2. OUTLINE
1. Introduction
2. The dynamical fluctuations inside 2-jets
3. The dynamical fluctuations inside 3-jets
4. The dynamical fluctuations inside single-jets
5. Conclusion

3. 1.1 The evolutive process in e+e- collisions
1. Introduction
1.1 The evolutive process in e+e- collisions
 QCD —— The basic theory of strong interaction
Question：• It is hard difficulty to calculate in soft processes by QCD；
• The partons haven’t been right observed as color confinement.

4. 1.2 Jet finding • 2-jet event in 1975, EC = 6 GeV；

5. 1.3

6. 1.4 The method described non-linear dynamical fluctuation
• NFM can characterize the dynamical fluctuation
• Saturation exponent —— the parameter of dynamical fluctuation
• If pt =  = y isotropy
If pt    y， anisotropy

7. 1.5 The method described non-linear dynamical fluctuation
Self-affine fractal
pt    y
Self-similar fractal
pt =  = y
h-h collision pt =   y Anisotropy in space
e+e- collision pt =  = y Isotropy in space

8. 2. The dynamical fluctuations inside 2-jets L.S. Liu, G. Chen and Q.H. Fu ，Phys. Rev. D63 （2001） G. Chen，K.S. Zhang and L.S. Liu L，SCIENCE IN CHINA G 46(3)（2003）

9. The dynamical fluctuations inside 2-jets Chen Gang, Hu Yuan, Liu Lianshou, W. Kittel, W.J. Metzger(L3 Collab.) XXXI ISMD, Datong Sept. 2001, (WORLD SCIENTIFIC).
The result is similar as same as MC simulation, exist a transition point

10. 2. The dynamical fluctuations inside 2-jets
· Analysis of the result from 2-jet sub-sample
It is the boundary of physical jet or circular jet.

11. 3. The dynamical fluctuations inside 3-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D
• Phase space: -5 < y <5, 0< pt< 3GeV, 0 < φ< 2π • The plot of γ ～ kt cut (ycut)
According to the symmetry of QCD Lagrangian, the gluon emission is isotropic, so the dynamical symmetry of 3-jet events is spherical. .
Appropriate scale of jet production
GeV (Jetset7.4), GeV(Herwig5.9)

12. 4. The dynamical fluctuations inside single-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D
• The jet axis as the z axis
• Phase space: 0 < y <5, 0< pt< 3GeV, 0 < φ< 2π • The plot of γ ～ kt cut (ycut)
• The dynamical fluctuation in azimuth appear
GeV
(Jetset7.4)
GeV
(Herwig5.9)

13. 4. The dynamical fluctuations inside single-jets Chen Gang，Yu Meiling and Liu Lianshou, Submiting to Phys. Rev.D
• The jet axis as the z axis
• Phase space: 0 < y <5, 0< pt< 3GeV, 0 < φ< 2π • The plot of γ ～ kt cut (ycut)
• The dynamical fluctuation in azimuth appear
• Obtain a scale
GeV
(Jetset7.4)
GeV
(Herwig5.9)

14. 5. Conclusion . • Listed the scales found in Table 1
The coincidence of the scales obtained from different origins is remarkable. All of them are related to jet production, so we give them a unique name .
jet production scale:
GeV

15. 5. Conclusion The jets in 2-jet events produced with is circular with
respect to dynamical fluctuations, i.e. the dynamical fluctuations in these jets is circular in the transverse plane. These jets have axial dynamical symmetry as expected by QCD.
2. When a third jet is produced with the resulting 3-jet system is isotropic in consistent with QCD expectation.
3. Inside a single jet, when it emits a gluon with , the
dynamical fluctuations in azimuthal angle appear suddenly inside this jet,
which means that the jet emitting gluon with is fully
developed, and the emitted gluon is hard enough to be the ``mother'' of a
new jet.

16. 谢 谢 ！